The caption initially named all the spouses of NATO leaders who were posing in the photo ― except for one: Gauthier Destenay, the first gentleman of Luxembourg and husband to Prime Minister Xavier Bettel.

Twitter users were quick to point out the missing name and accused the White House of doing it on purpose. Scott Bixby of The Daily Beast called the caption “homophobic.”

Is there a reason the @WhiteHouse didn't include the First Gentleman of Luxembourg in this photo caption?

Bettel and Destenay were in a civil partnership when Bettel became Prime Minister in 2013. They officially married two years later, when Luxembourg legalized marriage equality in 2015. Bettle is the only openly gay prime minister in the world.

People celebrated Destenay after photos of him with other world leaders’ spouses were published Friday. Some called his presence in the photo a symbol of equality for the LGBTQ community.

Though officials edited the original Facebook caption to include Destenay, some of the photo’s most-liked comments, including one from the Gay & Lesbian Alliance Against Defamation, are a clear reminder of the mistake the White House made.